Revert USB: usb-serial ch341: support for DTR/RTS/CTS
authorGreg Kroah-Hartman <gregkh@suse.de>
Tue, 7 Apr 2009 18:56:32 +0000 (11:56 -0700)
committerGreg Kroah-Hartman <gregkh@suse.de>
Fri, 17 Apr 2009 17:50:26 +0000 (10:50 -0700)
Reverts commit 664d5df92e88b6ef091048a802b3750f4e989180 as the commit
log information was not complete, and we didn't have a proper
signed-off-by by the author of the original BSD code.

Cc: Werner Cornelius <Werner.Cornelius@cornelius-consult.de>
Cc: Boris Hajduk <boris@hajduk.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
drivers/usb/serial/ch341.c

index ab4cc27..d33d39d 100644 (file)
@@ -1,7 +1,5 @@
 /*
  * Copyright 2007, Frank A Kingswood <frank@kingswood-consulting.co.uk>
- * Copyright 2007, Werner Cornelius <werner@cornelius-consult.de>
- * Copyright 2009, Boris Hajduk <boris@hajduk.org>
  *
  * ch341.c implements a serial port driver for the Winchiphead CH341.
  *
 #include <linux/usb/serial.h>
 #include <linux/serial.h>
 
-#define DEFAULT_BAUD_RATE 9600
+#define DEFAULT_BAUD_RATE 2400
 #define DEFAULT_TIMEOUT   1000
 
-/* flags for IO-Bits */
-#define CH341_BIT_RTS (1 << 6)
-#define CH341_BIT_DTR (1 << 5)
-
-/******************************/
-/* interrupt pipe definitions */
-/******************************/
-/* always 4 interrupt bytes */
-/* first irq byte normally 0x08 */
-/* second irq byte base 0x7d + below */
-/* third irq byte base 0x94 + below */
-/* fourth irq byte normally 0xee */
-
-/* second interrupt byte */
-#define CH341_MULT_STAT 0x04 /* multiple status since last interrupt event */
-
-/* status returned in third interrupt answer byte, inverted in data
-   from irq */
-#define CH341_BIT_CTS 0x01
-#define CH341_BIT_DSR 0x02
-#define CH341_BIT_RI  0x04
-#define CH341_BIT_DCD 0x08
-#define CH341_BITS_MODEM_STAT 0x0f /* all bits */
-
-/*******************************/
-/* baudrate calculation factor */
-/*******************************/
-#define CH341_BAUDBASE_FACTOR 1532620800
-#define CH341_BAUDBASE_DIVMAX 3
-
 static int debug;
 
 static struct usb_device_id id_table [] = {
@@ -66,12 +34,9 @@ static struct usb_device_id id_table [] = {
 MODULE_DEVICE_TABLE(usb, id_table);
 
 struct ch341_private {
-       spinlock_t lock; /* access lock */
-       wait_queue_head_t delta_msr_wait; /* wait queue for modem status */
-       unsigned baud_rate; /* set baud rate */
-       u8 line_control; /* set line control value RTS/DTR */
-       u8 line_status; /* active status of modem control inputs */
-       u8 multi_status_change; /* status changed multiple since last call */
+       unsigned baud_rate;
+       u8 dtr;
+       u8 rts;
 };
 
 static int ch341_control_out(struct usb_device *dev, u8 request,
@@ -107,28 +72,37 @@ static int ch341_set_baudrate(struct usb_device *dev,
 {
        short a, b;
        int r;
-       unsigned long factor;
-       short divisor;
 
        dbg("ch341_set_baudrate(%d)", priv->baud_rate);
-
-       if (!priv->baud_rate)
+       switch (priv->baud_rate) {
+       case 2400:
+               a = 0xd901;
+               b = 0x0038;
+               break;
+       case 4800:
+               a = 0x6402;
+               b = 0x001f;
+               break;
+       case 9600:
+               a = 0xb202;
+               b = 0x0013;
+               break;
+       case 19200:
+               a = 0xd902;
+               b = 0x000d;
+               break;
+       case 38400:
+               a = 0x6403;
+               b = 0x000a;
+               break;
+       case 115200:
+               a = 0xcc03;
+               b = 0x0008;
+               break;
+       default:
                return -EINVAL;
-       factor = (CH341_BAUDBASE_FACTOR / priv->baud_rate);
-       divisor = CH341_BAUDBASE_DIVMAX;
-
-       while ((factor > 0xfff0) && divisor) {
-               factor >>= 3;
-               divisor--;
        }
 
-       if (factor > 0xfff0)
-               return -EINVAL;
-
-       factor = 0x10000 - factor;
-       a = (factor & 0xff00) | divisor;
-       b = factor & 0xff;
-
        r = ch341_control_out(dev, 0x9a, 0x1312, a);
        if (!r)
                r = ch341_control_out(dev, 0x9a, 0x0f2c, b);
@@ -136,18 +110,19 @@ static int ch341_set_baudrate(struct usb_device *dev,
        return r;
 }
 
-static int ch341_set_handshake(struct usb_device *dev, u8 control)
+static int ch341_set_handshake(struct usb_device *dev,
+                              struct ch341_private *priv)
 {
-       dbg("ch341_set_handshake(0x%02x)", control);
-       return ch341_control_out(dev, 0xa4, ~control, 0);
+       dbg("ch341_set_handshake(%d,%d)", priv->dtr, priv->rts);
+       return ch341_control_out(dev, 0xa4,
+               ~((priv->dtr?1<<5:0)|(priv->rts?1<<6:0)), 0);
 }
 
-static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
+static int ch341_get_status(struct usb_device *dev)
 {
        char *buffer;
        int r;
        const unsigned size = 8;
-       unsigned long flags;
 
        dbg("ch341_get_status()");
 
@@ -159,15 +134,10 @@ static int ch341_get_status(struct usb_device *dev, struct ch341_private *priv)
        if (r < 0)
                goto out;
 
-       /* setup the private status if available */
-       if (r == 2) {
-               r = 0;
-               spin_lock_irqsave(&priv->lock, flags);
-               priv->line_status = (~(*buffer)) & CH341_BITS_MODEM_STAT;
-               priv->multi_status_change = 0;
-               spin_unlock_irqrestore(&priv->lock, flags);
-       } else
-               r = -EPROTO;
+       /* Not having the datasheet for the CH341, we ignore the bytes returned
+        * from the device. Return error if the device did not respond in time.
+        */
+       r = 0;
 
 out:   kfree(buffer);
        return r;
@@ -210,7 +180,7 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
                goto out;
 
        /* expect 0xff 0xee */
-       r = ch341_get_status(dev, priv);
+       r = ch341_get_status(dev);
        if (r < 0)
                goto out;
 
@@ -222,12 +192,12 @@ static int ch341_configure(struct usb_device *dev, struct ch341_private *priv)
        if (r < 0)
                goto out;
 
-       r = ch341_set_handshake(dev, priv->line_control);
+       r = ch341_set_handshake(dev, priv);
        if (r < 0)
                goto out;
 
        /* expect 0x9f 0xee */
-       r = ch341_get_status(dev, priv);
+       r = ch341_get_status(dev);
 
 out:   kfree(buffer);
        return r;
@@ -246,10 +216,9 @@ static int ch341_attach(struct usb_serial *serial)
        if (!priv)
                return -ENOMEM;
 
-       spin_lock_init(&priv->lock);
-       init_waitqueue_head(&priv->delta_msr_wait);
        priv->baud_rate = DEFAULT_BAUD_RATE;
-       priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
+       priv->dtr = 1;
+       priv->rts = 1;
 
        r = ch341_configure(serial->dev, priv);
        if (r < 0)
@@ -262,35 +231,6 @@ error:     kfree(priv);
        return r;
 }
 
-static void ch341_close(struct tty_struct *tty, struct usb_serial_port *port,
-                               struct file *filp)
-{
-       struct ch341_private *priv = usb_get_serial_port_data(port);
-       unsigned long flags;
-       unsigned int c_cflag;
-
-       dbg("%s - port %d", __func__, port->number);
-
-       /* shutdown our urbs */
-       dbg("%s - shutting down urbs", __func__);
-       usb_kill_urb(port->write_urb);
-       usb_kill_urb(port->read_urb);
-       usb_kill_urb(port->interrupt_in_urb);
-
-       if (tty) {
-               c_cflag = tty->termios->c_cflag;
-               if (c_cflag & HUPCL) {
-                       /* drop DTR and RTS */
-                       spin_lock_irqsave(&priv->lock, flags);
-                       priv->line_control = 0;
-                       spin_unlock_irqrestore(&priv->lock, flags);
-                       ch341_set_handshake(port->serial->dev, 0);
-               }
-       }
-       wake_up_interruptible(&priv->delta_msr_wait);
-}
-
-
 /* open this device, set default parameters */
 static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
                                struct file *filp)
@@ -302,13 +242,14 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
        dbg("ch341_open()");
 
        priv->baud_rate = DEFAULT_BAUD_RATE;
-       priv->line_control = CH341_BIT_RTS | CH341_BIT_DTR;
+       priv->dtr = 1;
+       priv->rts = 1;
 
        r = ch341_configure(serial->dev, priv);
        if (r)
                goto out;
 
-       r = ch341_set_handshake(serial->dev, priv->line_control);
+       r = ch341_set_handshake(serial->dev, priv);
        if (r)
                goto out;
 
@@ -316,16 +257,6 @@ static int ch341_open(struct tty_struct *tty, struct usb_serial_port *port,
        if (r)
                goto out;
 
-       dbg("%s - submitting interrupt urb", __func__);
-       port->interrupt_in_urb->dev = serial->dev;
-       r = usb_submit_urb(port->interrupt_in_urb, GFP_KERNEL);
-       if (r) {
-               dev_err(&port->dev, "%s - failed submitting interrupt urb,"
-                       " error %d\n", __func__, r);
-               ch341_close(tty, port, NULL);
-               return -EPROTO;
-       }
-
        r = usb_serial_generic_open(tty, port, filp);
 
 out:   return r;
@@ -339,194 +270,38 @@ static void ch341_set_termios(struct tty_struct *tty,
 {
        struct ch341_private *priv = usb_get_serial_port_data(port);
        unsigned baud_rate;
-       unsigned long flags;
 
        dbg("ch341_set_termios()");
 
-       if (!tty || !tty->termios)
-               return;
-
        baud_rate = tty_get_baud_rate(tty);
 
-       priv->baud_rate = baud_rate;
-
-       if (baud_rate) {
-               spin_lock_irqsave(&priv->lock, flags);
-               priv->line_control |= (CH341_BIT_DTR | CH341_BIT_RTS);
-               spin_unlock_irqrestore(&priv->lock, flags);
-               ch341_set_baudrate(port->serial->dev, priv);
-       } else {
-               spin_lock_irqsave(&priv->lock, flags);
-               priv->line_control &= ~(CH341_BIT_DTR | CH341_BIT_RTS);
-               spin_unlock_irqrestore(&priv->lock, flags);
+       switch (baud_rate) {
+       case 2400:
+       case 4800:
+       case 9600:
+       case 19200:
+       case 38400:
+       case 115200:
+               priv->baud_rate = baud_rate;
+               break;
+       default:
+               dbg("Rate %d not supported, using %d",
+                       baud_rate, DEFAULT_BAUD_RATE);
+               priv->baud_rate = DEFAULT_BAUD_RATE;
        }
 
-       ch341_set_handshake(port->serial->dev, priv->line_control);
+       ch341_set_baudrate(port->serial->dev, priv);
 
        /* Unimplemented:
         * (cflag & CSIZE) : data bits [5, 8]
         * (cflag & PARENB) : parity {NONE, EVEN, ODD}
         * (cflag & CSTOPB) : stop bits [1, 2]
         */
-}
-
-static int ch341_tiocmset(struct tty_struct *tty, struct file *file,
-                         unsigned int set, unsigned int clear)
-{
-       struct usb_serial_port *port = tty->driver_data;
-       struct ch341_private *priv = usb_get_serial_port_data(port);
-       unsigned long flags;
-       u8 control;
-
-       spin_lock_irqsave(&priv->lock, flags);
-       if (set & TIOCM_RTS)
-               priv->line_control |= CH341_BIT_RTS;
-       if (set & TIOCM_DTR)
-               priv->line_control |= CH341_BIT_DTR;
-       if (clear & TIOCM_RTS)
-               priv->line_control &= ~CH341_BIT_RTS;
-       if (clear & TIOCM_DTR)
-               priv->line_control &= ~CH341_BIT_DTR;
-       control = priv->line_control;
-       spin_unlock_irqrestore(&priv->lock, flags);
-
-       return ch341_set_handshake(port->serial->dev, control);
-}
-
-static void ch341_read_int_callback(struct urb *urb)
-{
-       struct usb_serial_port *port = (struct usb_serial_port *) urb->context;
-       unsigned char *data = urb->transfer_buffer;
-       unsigned int actual_length = urb->actual_length;
-       int status;
-
-       dbg("%s (%d)", __func__, port->number);
-
-       switch (urb->status) {
-       case 0:
-               /* success */
-               break;
-       case -ECONNRESET:
-       case -ENOENT:
-       case -ESHUTDOWN:
-               /* this urb is terminated, clean up */
-               dbg("%s - urb shutting down with status: %d", __func__,
-                   urb->status);
-               return;
-       default:
-               dbg("%s - nonzero urb status received: %d", __func__,
-                   urb->status);
-               goto exit;
-       }
-
-       usb_serial_debug_data(debug, &port->dev, __func__,
-                             urb->actual_length, urb->transfer_buffer);
-
-       if (actual_length >= 4) {
-               struct ch341_private *priv = usb_get_serial_port_data(port);
-               unsigned long flags;
-
-               spin_lock_irqsave(&priv->lock, flags);
-               priv->line_status = (~(data[2])) & CH341_BITS_MODEM_STAT;
-               if ((data[1] & CH341_MULT_STAT))
-                       priv->multi_status_change = 1;
-               spin_unlock_irqrestore(&priv->lock, flags);
-               wake_up_interruptible(&priv->delta_msr_wait);
-       }
-
-exit:
-       status = usb_submit_urb(urb, GFP_ATOMIC);
-       if (status)
-               dev_err(&urb->dev->dev,
-                       "%s - usb_submit_urb failed with result %d\n",
-                       __func__, status);
-}
-
-static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
-{
-       struct ch341_private *priv = usb_get_serial_port_data(port);
-       unsigned long flags;
-       u8 prevstatus;
-       u8 status;
-       u8 changed;
-       u8 multi_change = 0;
-
-       spin_lock_irqsave(&priv->lock, flags);
-       prevstatus = priv->line_status;
-       priv->multi_status_change = 0;
-       spin_unlock_irqrestore(&priv->lock, flags);
-
-       while (!multi_change) {
-               interruptible_sleep_on(&priv->delta_msr_wait);
-               /* see if a signal did it */
-               if (signal_pending(current))
-                       return -ERESTARTSYS;
-
-               spin_lock_irqsave(&priv->lock, flags);
-               status = priv->line_status;
-               multi_change = priv->multi_status_change;
-               spin_unlock_irqrestore(&priv->lock, flags);
-
-               changed = prevstatus ^ status;
-
-               if (((arg & TIOCM_RNG) && (changed & CH341_BIT_RI)) ||
-                   ((arg & TIOCM_DSR) && (changed & CH341_BIT_DSR)) ||
-                   ((arg & TIOCM_CD)  && (changed & CH341_BIT_DCD)) ||
-                   ((arg & TIOCM_CTS) && (changed & CH341_BIT_CTS))) {
-                       return 0;
-               }
-               prevstatus = status;
-       }
-
-       return 0;
-}
-
-/*static int ch341_ioctl(struct usb_serial_port *port, struct file *file,*/
-static int ch341_ioctl(struct tty_struct *tty, struct file *file,
-                       unsigned int cmd, unsigned long arg)
-{
-       struct usb_serial_port *port = tty->driver_data;
-       dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
-
-       switch (cmd) {
-       case TIOCMIWAIT:
-               dbg("%s (%d) TIOCMIWAIT", __func__,  port->number);
-               return wait_modem_info(port, arg);
-
-       default:
-               dbg("%s not supported = 0x%04x", __func__, cmd);
-               break;
-       }
-
-       return -ENOIOCTLCMD;
-}
-
-static int ch341_tiocmget(struct tty_struct *tty, struct file *file)
-{
-       struct usb_serial_port *port = tty->driver_data;
-       struct ch341_private *priv = usb_get_serial_port_data(port);
-       unsigned long flags;
-       u8 mcr;
-       u8 status;
-       unsigned int result;
-
-       dbg("%s (%d)", __func__, port->number);
-
-       spin_lock_irqsave(&priv->lock, flags);
-       mcr = priv->line_control;
-       status = priv->line_status;
-       spin_unlock_irqrestore(&priv->lock, flags);
-
-       result = ((mcr & CH341_BIT_DTR)         ? TIOCM_DTR : 0)
-                 | ((mcr & CH341_BIT_RTS)      ? TIOCM_RTS : 0)
-                 | ((status & CH341_BIT_CTS)   ? TIOCM_CTS : 0)
-                 | ((status & CH341_BIT_DSR)   ? TIOCM_DSR : 0)
-                 | ((status & CH341_BIT_RI)    ? TIOCM_RI  : 0)
-                 | ((status & CH341_BIT_DCD)   ? TIOCM_CD  : 0);
-
-       dbg("%s - result = %x", __func__, result);
 
-       return result;
+        /* Copy back the old hardware settings */
+        tty_termios_copy_hw(tty->termios, old_termios);
+        /* And re-encode with the new baud */
+        tty_encode_baud_rate(tty, baud_rate, baud_rate);
 }
 
 
@@ -564,17 +339,12 @@ static struct usb_serial_driver ch341_device = {
                .owner  = THIS_MODULE,
                .name   = "ch341-uart",
        },
-       .id_table          = id_table,
-       .usb_driver        = &ch341_driver,
-       .num_ports         = 1,
-       .open              = ch341_open,
-       .close             = ch341_close,
-       .ioctl             = ch341_ioctl,
-       .set_termios       = ch341_set_termios,
-       .tiocmget          = ch341_tiocmget,
-       .tiocmset          = ch341_tiocmset,
-       .read_int_callback = ch341_read_int_callback,
-       .attach            = ch341_attach,
+       .id_table         = id_table,
+       .usb_driver       = &ch341_driver,
+       .num_ports        = 1,
+       .open             = ch341_open,
+       .set_termios      = ch341_set_termios,
+       .attach           = ch341_attach,
 };
 
 static int __init ch341_init(void)